Lymphatic filariasis caused by the filarial nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori, affects more than 120 million people worldwide (WHO (1992) World Health Organ. Tech. Rep. Ser. 821:1-71). Mass drug administration program by the World Health Organization, is significantly reducing the incidence rate of lymphatic filariasis in many parts of the world (Hotez (2009) Clin. Pharmacol. Ther. 85(6):659-64). Nevertheless, lack of effectiveness to the mass drug administration has been reported from several endemic regions mainly due to noncompliance (Babu & (2008) Trans. R. Soc. Trop. Med. Hyg. 102(12):1207-13; El-Setouhy, et al. (2007) Am. J. Trop. Med. Hyg. 77(6):1069-73). In addition, drug resistance has been reported to at least one of the drugs in the mass drug combination (Horton (2009) Ann. Trop. Med. Parasitol. 103(1):S33-40; Schwab, et al. (2007) Parasitology 134(Pt 7):1025-40). Since yearly administration of the mass drugs is required for effective control, there is an alarming concern for selecting drug resistant parasites. Therefore, there is an immediate need for a multipronged approach in controlling this mosquito borne infection.
Vaccination is one strategy for controlling this infection and several subunit candidate vaccine antigens have been tested in laboratory animals with variable results (Bottazzi, et al. (2006) Expert Rev. Vaccines 5(2):189-98; Chenthamarakshan, et al. (1995) Parasite Immunol. 17(6):277-85; Dissanayake, et al. (1995) Am. J. Trop. Med. Hyg. 53(3):289-94; Li, et al. (1993) J. Immunol. 150(5):1881-5; Maizels, et al. (2001) Int. J. Parasitol. 31(9):889-98; Thirugnanam, et al. (2007) Exp. Parasitol. 116(4):483-91; Veerapathran, et al. (2009) PLoS Negl. Trop. Dis. 3(6):e457). Lymphatic filariasis is a multicellular organism with complex life cycle and produce large array of host modulatory molecules. Thus, fighting against this infection with a single antigen vaccine can be difficult. By screening a phage display cDNA expression library of the B. malayi parasite with sera from immune individuals, several potential vaccine candidates were identified (Gnanasekar, et al. (2004) Infect. Immun. 72(8):4707-15). However, a varying degree of protection was achieved with each of the candidate vaccine antigens when given as a DNA, protein or prime boost vaccine (Veerapathran, et al. (2009) supra).